1. Technical Field of the Invention
The present invention relates to a wide-angle lens assembly for use in a monitor camera or a vehicle-mounted camera.
2. Description of Related Art
Wide-angle lens assemblies used in a monitor camera or a vehicle-mounted camera have been desired to be less in cost and size while keeping high performance.
A conventional compact type wide-angle lens system having a 70 to 90 degrees horizontal angle of view consists of two optical lenses. Also, another compact wide-angle lens system having a horizontal viewing angle of 90 to 120 degrees consists of three optical lenses.
In order to construct six different lens groups respectively having a viewing angle of 70.degree., 80.degree., 90.degree., 100.degree., 110.degree., and 120.degree. in such conventional wide-angle lens systems, it is necessary to provide a total of 15 lenses even with the use of aspherical resin lenses; two lenses for each of the viewing angles from 70.degree. to 90.degree. and three lenses for each of the viewing angles from 100.degree. to 120.degree.. The lenses have to be fabricated with different sets of molds, thus increasing the cost of production.